Muffler



June 3, 1924.

A. H. ABELL ET AL MUFFLER Filed Nov. 2, 1917 2 Sheets-Sheet 1 June 3, 1924.

A. H. ABELL ET AL MUFFLER Filed Nov. l2, 1917 2 Sheets-Sheet 2 WM MWA Afromfv Patented June 3, 1924.

UNITED STATES PATENT GFFICE.

AMHUR H. ABEL, OF NEW YORK, N. Y., AND WILLIAM H. FULTON, 0F IBVINGTON,

NEW JERSEY, ASSIGNORS T0 TITEFLEX IETLL HOSE CORPORATION, A CORPORA- TION 0l m YORK.

IUFFLEB.

To all .whom it may concern.

Be it known that we, ARTHUR H. Ani-:LL and IVILLIAM H. FULTON, citizens of the United States, residing at city, county, and

`State of New York, and Irvington, Union County, State of New Jersey, respectively, have invented new and useful Improvements in Mulers, of which the following is :a speciiication.

This invention relates to devices for reducing the noise of exhausting of gases from internal combustion engines and the like.

Where the noise is lessened principall b choking back the exhaust gases, the ac pressure on the en ine is greatly increased and the eiliciency o the engine impaired. If the pressure of the gasesis reduced by cooling and conse uent condensation, the noise is reduced whi be increased and may even be made smaller. If a tube is unobstructed, or is otherwise arranged so that gases may flow'through it in interior paths removed from the wa ls, the

ases in such paths will be jacketed by, and ghe heat radiation therefrom retarded by, the outer layers of gases adjacent the tube walls. If means is su plied to break up the interior paths and de ect the ases from the interior outwardly to the wal s, the cooling of the gases and eiliciency of the apparatus both as a muler and in its effect upon the back pressure is greatly increased. In order to meet commercial requirements however, the a paratus must not be complicated.

It is one object of the invention to take advantage of the conditions referred to, to produce eicient muling with simple apparatus.

It is a further object of the invention to employ a corrugated tube in this relation, the corrugations against which the gases are thrown causing eddies against the walls whereby the cooling is greatly promoted.

A further object of the invention is to provide` in this relation a corrugated tube which, being formed of a grooved helical strip, has its joint or seam at the bases of the corrugations instead of at their outermost portions. The most eilicient radiating surfaces i. e., the outermost ortions, are thus left of but one thickness of) metal so that the cooling is enhanced.

A further object of the invention is to provide a deilector structure in the form of an insert for a tube so that upon its ine the back pressure need not l sertion in a tube an efficient muier is formed.

l Other and ancillary objects of the inveiition will appear hereinafter. i

In the accompanying drawings which illustrate the invention- Fi ure 1 is a side elevation ofan automobi e partly broken away, showing the location of the exhaust connections, including the muiller;

Fig. 2 is a side elevation, partly broken away and partly in section of the muiller;

Fig. 3 is an end elevation of the niuier shiwn in Fig. 2, viewed from the left hand si e;

Fig. 4 is a view of a portion of the muffler on the same scale as Fig. 3, the tube being shown in longitudinal axial section;

Fig. 5 is a pers wective view of the deflector structure adapte to be inserted in the tube:

Fig. 6 is a top plan view on an enlarged scale of the device at the termination of the exhaust pipe whereby the exit orifice is shaped into a relatively lon and nari-ow slot, which structure is usua y referred to as a fish-tail;

7 is an end elevation of the fishtail;

Fig. 8 is a view similar to Fig. 3, but showing a modified form of defiector structure; and

Fig. 9 is a view similar to Fig. 4 showing' a modified structure of the corrugated tube.

Referrin to the drawings and first to Figures '1- inclusive, the engine 1 of an automobile 2, has the helically corrugated pipe 3 connected with the exhaust manifold and extending therefrom to the rear of the car or other appropriate point for the release of the exhaust into the atmosphere. The helically corrugated pipe may be integrall formed, as for instance, is shown in the atent No. 1,120,268, dated December 8th, 1914, or it may be formed from a longitudinall grooved helical strip having the edges o adjacent convolutions interfolded, as for instance, is shown in the Patent No. 1,198,392, dated September 12th, i916, or it may be varied in structure or manufacture in other suitable ways. The tube structure may be as shown in Fig. 4 wherein a strip 4, havin a groove 5, also has upon one edge a curv flange 6 and on the other edge a curved flange 7. The strip is then formed into a helix with the flange 6 nestin within the flange 7. The joint or over-lap ing at the outermost portion of the wall of the tube. Within the tube is. inserted a sheet metal strip comprising a diaphragm 8, upon opposite sides of which extend the defiectors 9 for the exhaust gases. At the longitudinal edges of the diaphragm are flanges 10 and 11, which extend on opposite sides of the diaphragm and the diaphragm and aiiges are so proportioned that the sides ot' the diaphragm do not bear against the pipe, but the anges spring against the tube walls and hold the diaphragm in; position. This does away with the necessity of any n icety of fitting of the deilector structure within the tube and at the same time secures it against rattling. Moreover it facilitates the shding of the structure lengthwise into the tube. It will be observed that alternate deiiectors 9 extend on opposite sides of the diaphragm. and between successive deiectors are the holes 12. Furthermore it will be observed that the deiiectors 9 make angles of approximately 60 with the diaphragm, being inclined backwardly, that is, toward the engine and away from the tail of the exhaust. It will be seen that at any one point the gas passage through the tube is approximately one-half the area of the tube and that the gases in passing through the tube when the defiectoi' structure is present, pass upon one side of the diaphragm, come against one side of a deiiector, pass through a hole 12 in the diaphragm to the opposite side of the da hragm and, encountering the succeeding de ector, are again diverted in the succeeding hole 12 in the diaphragm to the first side thereof and so the gases are kept zig-zagging from one side of the tube to the other. In order that the openings 12 in the diaphragm should aiiord a passage for the gases which will not throttle the same, each ofethese holes should be of an area,not less than one-half of the area of the tube cross-section. The inclination of the deiiectors as described, serves to gradually deflect the gases instead of causing abrupt im act thereby reducing the back pressure, while serving to deflect the gases against the walls of the pipe so that the cooling and condensing eli'ect thereon are very greatly increased. It should be observed that the diaphragm is located at the center of the tube and the gases are deected outwardly therefrom so that there canno-t be any current of hot gas {iowing along the center of the tube and therefore jacketed by gases nearer the wall of the tube from the cooling effect of the atmosphere. The cooling of the gases is thereby greatly promoted, the gases being directed from the center of the tube outwardly into the corrugations repeatedly so that the gases are thoroughly roken up and brought into cooling contact with the large radiating surfacel provided by the corrugations. Also the fact that the corrugations are helically formed causes the gases defiected' outwardly into them, to be given a swirling motion about` then bent outwardly from the plane of the strip alternately on opposite sides thereof,

each defiector being secured to the strip by the uncut portion of its periphery. In the structure shown herein the delectors are at angles of 60 to the strip and substantially conform tothe interior of the tube, the cut portions of the peripheries of the deiectors and consequent y the holes 12 in the strip from which they are removed, will be semi-elliptical inform. The longitudinal flanges 10 and l1 at the edges of the strip are bent in opposite directions. The insert thus formed may have its end inserted within the exit end of the tube and pushed in to the desired extent. The deflector structure may be in the end of an exhaust tube or it may be located at any point in the `exhaust pipe and different lengths may be employed according to the desired results, the length depending upon the number of defiectors necessary and their spacing along the strip. The fishtail structure 13, having a narrow and long outlet 14, and a circular inlet opening 15, is provided with ears 16 for securing to a support and may be secured to the end of the pipe by means of screw threads 17 formed in the circular portion of the fishtail structure and adapted to receive the helical corrugations of the end of the tube. After having been screwed on to the end of the tube the fishtail may be secured in position by means of a set screw 18. This structure effectively prevents whistling due to swirling of the escaping gases, which swirl may be imparted by the helical corrugations or otherwise.

Referring now to Fig. 8, a modified form of deflector insert is shown, wherein` the strip having the deiiectors 19, the same as the deliectors 9 of the preceding structure, does not have its longitudinal edges 20 and 21 bent at an angle to the plane of the strip but the strip is formed by simply cutting the diaphragm and bending out the deflectois. This leaves spaces between the edges of the deilectors and the tube walls as shown, but in some structures it may not be objectionable and may 4even be desirable in order to decrease the back pressure. It will be observed that the clearances thus formed, or other clearances which may I is not therefore limited to the structures exist about the edges of the defiectors permit a portion of the gases to pass the deflectors Without going through the diaphragm but in effecting such passage or leakage the gases are obliged to pass along the Walls of the tube so that they do not escape the cooling action.

Referring now to Fig. 9, there is therein shown a deflector structure the same as that in Fig. 5, but the tube is constructed of a longitudinally grooved helically disposed strip having the longitudinal groove 22, the angular flange 23 at one margin and the U shaped flange 24 along the other side, the flange 23 being nested Within the flange 24 in the tube as shown in Fig. 9. It Will be observed that the over-lap or joint is at the innermost portion ofthe wall of the tube and this is of advantage for the reason that there is but one thickness of metal at the outer portions of the corrugations so that 4the heat may be more readily radiated at the point of most ready dissipation. Other forms of tubing may also be employed and the deflector structure is advantageous in smooth uncorrugated tubes and various other tube structures. While the invention has been illustrated in What are considered its best applications, it may have other embodiments and other uses without departing from its spirit and shown in the drawings, the invention being pointed out in accordance with the patent statutes in the appended claims.

What We. claim is- 1. The combination With a helically corrugated tube of a diaphragm extending across the interior of the tube and transverse to a diameter thereof, said diaphragm having spring flanges extending longitudinally along its edges. and deflectors extending from said diaphragm upon opposite sides thereof, said deflectors making acute angles With said diaphragm, said diaphragm having openings between successive deflectors.

2. The combination with a helically corrugated tube of an insert contained therein comprising a metal strip having deflectors punched therefrom by cutting about portion of their peripheries, the said deflectors being alternately bent in opposite directions from said strip and said strip having spring flanges bent to opposite sides of said strip and adapted to bear against the interior of the Walls of the tube to position the deflector structure, said deflectors making acute angles with the'plane of said strip.

In testimony whereof we have signed this specification this ls't day of November, 1917.

ARTHUR H. ABELL. WILLIAM H. FULTON. 

